Torchwood: Miracle Day star John Barrowman is a fanboy, having spent three hours — and several thousand dollars — on the San Diego Comic-Con convention hall floor Thursday evening, picking up T-shirts and action figures. “I’m like all of you,” he said to the crown on hand for the Starz series’ panel discussion. “I’m a fan of science fiction. I’m a nerd at heart, and I’m proud of it!” Not be outdone, Mekhi Phifer shared that “even though I’m from Harlem, I’m a big nerd too.”

Here is what else the Torchwood team had to share about a dark twist to come, the show’s legacy, and the (tear!) death of Ianto.

* With the 50th anniversary of BBC’s Doctor Who coming up in 2013, one topic of conversation was whether Captain Jack would return to Torchwood‘s “mothership,” as Barrowman put it. “I think there would be a different kind of dynamic there with Jack and the [new] doctor [played by Matt Smith],” Barrowman replied. “I’m totally up for it. I love playing Captain Jack. It’s the best coat I could put on every morning, so I’m up for it.”

* Alexa Havins’ naïve CIA agent may be a Torchwood novice right now, but as the series progresses, she’ll go through a mental and physical evolution. “I think she has the most growth of anyone,” the actress offered. “She falls for the whole team and finds her place.” But don’t look for her to displace the show’s original female rock star, by any means. “I don’t think she can reach Gwen’s badass level,” Havins noted, most accurately.

* The cast and crew are very happy to be on Starz, especially after Children of Earth‘s ominous ending. “When we finished with [that], it was written in a way that we actually thought it wasn’t going to come back,” said Barrowman, who was very vocal about wanting the series to continue. “Thank goodness for Starz, who stepped forward.… We wanted it to be with the right people, the right team, and they said, ‘We don’t want you to change the feel of the show. Just make it bigger and better.’”

* Look for Miracle Day to darken very soon. “If you are feeling hungry for dark chocolate, and you’ve been getting milk chocolate, wait for Episode 5,” executive producer Jane Espenson teased. Barrowman himself was excited for Episode 7, which series creator Russell Davies called “a gift” for longtime fans of the series. It features a new romantic “involvement” for Jack, as well as a lot of character exploration. “You learn a lot about Jack and Gwen in that episode,” said Barrowman. “That’s a major, major [episode]. Quite heavy and shocking.”

* Still hurting over the death of Ianto? That means the show has done it’s job, according to Barrowman. “We as a show love the fact that you are passionate about the characters,” he said. And although it was a tough goodbye, the storyline was necessary. “In a drama, you have to do things that will unfortunately upset [people] and cause change,” he continued. “In order to move the drama on, we had to do something drastic. He is still remembered and mentioned.”

* Where did Captain Jack go at the end of Children of Earth? Your guess is as good as Barrowman’s, and that question won’t be answered in Miracle Day, but maybe down the line. “[The show doesn’t] always have to give the answers to what has happened,” he said. “Make up what you want. I just think Jack had a great time with Alonso.”

* Wales’ cold weather during filming of Episode 1 was tough on Phifer. “Hey, I’m black,” he said with a smile. “I’m a tropical person.” Good thing the show quickly moved to L.A. for production. And should the series continue, Eve Myles would be more than happy to relocate again and enjoy the heat, as well as a particular Tinseltown staple. “In-N-Out Burger rocks my world,” she raved. “Those animal fries? Unbelievable.”